My favorite text editor/IDE is Sublime Text Editor. Its full power is realized when you use Package Control. The text editor is fast, the packages yield a lot of great functionality in an IDE, and best yet, writing your own packages is relatively easy.
Yes, the text editor is not free, but it is cross-platform: Mac, Windows, and Linux, and the licensing is generously attached to the user, not the machine. That means that if you buy a license, it can be used on any of your machines.
Package recommendations:
HTMLTidy – reformat HTML using Tidy
jQuery – jQuery auto-completions
Markdown Preview – Markdown renderer to see MD in your text editor
Nodejs – node.js auto-completions
SublimeCodeIntel – fuzzy logic code completion
SublimeLinter – lint your code on the fly – my fork discussed below
Theme – Soda – alternative theme for sublime
Tomorrow Color Scheme – alternative color scheme for sublime
SublimeLinter – wilco42 fork
SublimeLinter is a fantastic real-time code linter that will lint your code as you type, but if you are writing JavaScript code, you have to pick the default linting engine. Available engines are: jshint, jslint, and gjslint. jshint and jslint are similar enough that you can just pick one of those, but there are significant differences between the gjslint and jshint engines where running one or the other won’t catch all of your violations.
My fork adds a new engine which runs both jshint and gjslint. It’s a relatively simple change which calls both engines externally and applies the result in-editor. If you feel like you want to run both linters in your IDE, give it a whirl.